YSK high school history classes are only ever meant to serve as a basic introduction to your nation's history and you should not be so shocked when you learn later that it left a lot of stuff out
from /r/YouShouldKnow
YSK的高中歷史課只是作爲對你的國家歷史的基本介紹，當你後來知道它遺漏了很多東西時，你不應該如此震驚